Boiler amplifier



Oct. 16, 1945.

M. cycRm-rv l l 2,386,842

BOILER AAMPLIFIER Y Fiied oct. v1, 1945 6 Sheets-Sheet 2 9 4a 4/ fz laOct. 16, 1945. M, C. CROTTY HOHER-AMPLIFIER Filed 001'.. l, 1943 6Sheets-Sheet 4 Oct. 16, 1945. M. c. CROTTY BOILER AMPLIFIER Filed oct.1, 194s e sheets-.sheet 5 INVENTOR l/l'C/M/ @Cro Oct. 16, 1945. M. c.cRoTTY BOILER AMPLIFIER Filed 0G12. l, 1945 6 Sheets-Sheet 6 ma ma@Patented 16, 1945 BOILEB AMPLIFIER. Michael C. Crotty, Flushing, N. Y.,assignor to Crotty Manufacturing Corporation,

New York,

N. Y., a corporation of New York Application october i, 1943, semi No.504,561

(ci. 12e- 405) 7 Claims.

The present invention relates to boiler amplifiers or devices forincreasing the capacity of steam boilers. More particularly, the boileramplier of the invention is adapted to increase the steam 'generatingcapacity of a boiler and employs a forced circulation system. water fromthe boiler drums being pumped under constant pressure into a system oftubes of small diameter, and after being heated by fires within thecircuit of the tubes is returned to the drums mainly as steam. Byvarious structural means within the scope of the invention, the flowwitb'in the tube system of the device is prevented from expanding intosteam and forming steam pockets until it is returned to the drum, atwhich point the steam and hot water are permitted to separate;

The boiler amplifier is4 attached to the boiler and is an extension.thereof and its combustion chamber communicates with the combustionchamber of the boiler through an opening in the walls of the boiler. Itis thus outside the boiler proper but the gases of combustion from thedevice are permitted to flow into the combustion chamber of the boiler.

The amplifier of the invention has for its aim the more even use of heatand a greater recovery than is possible in conventional types of boilersand auxiliary apparatus at present in use with such boilers. .Manyattempts have been made and considerable work has been done inconnection with heat recovery as applied to steam boilers. To this endmany appliances have been designed such as steam superheaters,desuperheaters, air pre-heaters, appliances for utilizing the passing ofgases, etc. Most of these applications,

at top and bottom to headers, the water entering the lower header,circulating around both sides of the circular furnace land beingdischarged through the top header. The length of this furnace may beapproximatelyeight feet. It is set in front of an opening into thefiring space of the boiler which may be of anyconventional type,v

and one end of the cylindrical tube system is open and communicates,with the boilerfurnace space. It is preferably surrounded by arefractory covering, such as fire brick, and iinished with heatinhowever, are made ln connection with the iinal Y stage of the boilercombustion processthat is, the iinal gas outlet of the boiler betweenthe boiler and the smoke stack.

The amplier of the present. invention, however, eifects heat recovery atthe furnace end of the boiler. The instrumentality for accomplish-V ingthis end is a boiler extension which comprises a water walled furnace inwhich the com bustion takes place more or less centrally within theambit of tubes which wholly or partially surround the combustionchamber. If the fuel utilized is oil or powdered coal, the tubes willform preferably a cylindrical enclosure in which the res are centered.This cylinder may be, for instance, approximately six feet in diameterand may be constructed for best effects of seamless steel tubes having adiameter of from one inch to one and a quarter inches. These tubes arebent into a circular section and will be secured sulation material, suchas masonry or metal casing, so as to form a Dutch oven eil'ect.`

'I'he fuel bed or cone is thus moved from its accepted location withinthe combustion chamber of the boiler proper to a position outside theboiler and within the water walled furnace extension of the amplifier ofthis invention. The

4gases resulting from the combustion of fuel inA the amplier, however,pass through the open end of the amplier into the main boiler combustionchamber and thence through the usual boiler gas passage tothe smokestack.

In this amplifier I make useA of the principle of forced circulation,pumping the water from the boiler drum or drums andv forcing it throughthe water walled furnace extension or ampliiier where it collects itsheat from the fuel being burned. It is then carried by the action of thepumping in the form' of water and steam mixed back to the boiler drumwhere it is permitted to expand and separate steam from water. Controlsare used such as orifice plates or other pressure drop devices tocontrol the ilow of water and prevent expansion' before entering theboiler steam drums. f

In the past, attempts more or less successful have been made toconstruct boiler amplifiers or boosters as they were called. Generally,these consisted of tubes wrapped in a single layer helix without headersto provide for cleaning. It is also the case that boostersV of thisgeneral type have been made with a square section having headers locatedin an upper corner'and a lower corner. 4Such a construction accordinglyVconsisted of two perpendicular rows of tubes and two horizontal rows oftubes through which the water a single complete unit. The result is anunequal pressure of water within the various tubes permitting theformation of steam pockets. There v55 is consequently diiculty indraining and cleaning the tubes and unevenly distributedv strains andstresses result from violent temperature changes.

In the amplifier of the present invention, however, the tube system isnot a single continuous unit such as that just referred to. It is, infact, a plurality of short units or sections, each having an inlet'header' at the bottom and an outlet header at the tbp and each having aplurality of tubes of curved; contour embracing the iires.

Greater or less capacity can be had by adding or subtracting sections,and, by means of appropriate valves, one or more sections may be cut outfor cleaning or repair. Thus, cleaning or draining is facilitated andblowing down of any section may be effected by cutting out one sectionat a time and opening a valve provided for that purpose.

It is an object of the present invention to provide a boiler amplifiercomprising a system of tubes which more efliciently generate steam andwhich greatly increases the capacity of a boiler with which it is used.

It is a further object to provide a boiler amplifier the tube units ofwhich are constructed in sections of convenient size and capacity sothat sections can be added or removed to increase or decrease itscapacity.

It is a further object to provide an amplifier thatan be constructed,stress relieved and tested in a factory, and taken to the job site. Inthe past such furnace extensions or amplifiers had to be constructed onthe premises as they are of one-piece construction and could not betaken through ordinary door openings. The sectional construction of theamplifier of the present invention permits it to be taken section bysection through ordinary door openings.

The invention will be more clearly understood by reference to thedrawings in Which- Fig. 1 represents a front elevation of the boileramplifier of the invention, together with its connections with the drumsof the boiler;

Fig. 2 is a side elevation of the same with the boiler and a boiler drumpartially broken away;V

Fig. 3 is a plan view of the boiler amplifier and the boiler; A

Fig. 4 is a sectional elevation of the boiler ampliiler on the lines l-lof Fig. 2;

Fig. 5 is a side elevation of the amplifier tube assembly showing thesectional construction;

Fig. 6 is a detail showing the construction and mounting of the orificeplates;

Fig. I illustrates the construction of the end of a header;

Fig. 8 is a section of a header along the lines 8--8 of Fig. 'l showingthe method of joining the ampliiier tubes to the header;

Fig. 9 is a modification of the construction shown in Fig. 8;

Fig. 10 is a modified construction of the arnplifier shown in Fig. 4 buthaving two headers at the bottom and two headers at the top;

Fig. l11 is a plan view and Fig. 12 a side elevation showing a method ofconstruction of the ampliflenof the invention in which the riserscommunicate directlywith the drum of the boiler without any interveningheader;

Fig. 13 is a sectional elevation along the line I3-I3 of the coal stokedamplifier which is shown in Fig. 14; and

Fig. 14 i's a sectional elevation along the line I4-I4 of Fig. 13 withthe tube sections partially broken away.

Referring now to the drawings, Fig. 1 shows asada-ia a front elevationof a boiler of any conventional type having, in this instance. threedrums indicated at l, 2 and I. I of the invention is shown placed infrontA of the boiler. The heating unit 5, illustrated as an oil burningunit, feeds into the center of the combustion chamber around which thetubes i of the device are indicated in dotted line. From -the drum Iapipe 'I leads to a pump Il and subsidiary pipes l and l connect withpipe I at la and 9a and thus through pipe 'I with pump Il. Pump I0delivers the water from pipe 1 through pipe II to the tube sections, veof which are indicated at G, forming one complete unit. The number ofsuch sections may, of course, be greater or less than this numberaccording to the capacity increase desired or required. Shut of! valvesI2 and safety valves I3 are placed inthe connections of pipe Il betweenthe pump I0 and the sections 6 and a. pressure gauge Il is also mountedin pipe I I. The heated water passes from the tube sections 6 throughthe top headers I5, riser pipes I6, through orifice plates I8, I8a, Ib,llc and I8d, header I'I, and back to the Iboiler drums I, 2 and 3. Itwill be seen that header I1 is a manifold header communicating on oneside with 1each tube section top header I5 through riser pipes I6 and onthe other side with each boiler drum through a separate pipe connection.

A valve I9, I 9a, I9b, Isc and IQd is mounted between the orifice platesIl and the header I1 and pressure gauges 20, 20a, 20h, 20c and 20d aremounted between the riser pipes I8 and the orice plates I8.

'I'he detailed construction of the tube sections of the invention isshown in Fig. 4 which is a front elevation thereof and in Fig. 5 whichis a side elevation with the walls broken away. It will be seen that theinner side walls 2| are of refractory material, such as fire brick, andthe outer walls 22 of heat insulation material. An arch 23 sus- 'pendedfrom I-beams 2l forms the roof of the combustion chamber and isconstructed in manner similar to the walls. The oors also have the sameconstruction. However, where the tubes enter the combustion chamber, itis entirely of refractory material, as shown at 25. The drawings Fig. 4and Fig. 5 show a preferred construction of the tubes of the device. Itwill be noted that the pipe I I which, as above stated, leads from thepump I0, connects with the joint 26 which in turn connects with thebottom header 21 in such a manner that the water from pipe II isdirected into the header in alignment with the tubes 6 which meet theheader in a somewhat vertical position. It will also be seen from Fig. 5that the tubes 6 are divided into sections, each section having anindividual bottom header 21 and a top header I5, the former receivingthe flow from pipe II and the top discharging into the riser or pipe I6.The joint 26 connects with one end of the header 21 and at the dischargeend of the section the riser I6 connects with the top header I5 at themost remote opposite end from the inlet in bottom header 21. 'I'hisassures uniformity of circulation within the section.

The arrangement of the risers I6 will be seen from Figs. 2 and 3, Fig. 2being a side elevation of the amplifier and Fig. 3 a view from above. Itwill be noted that each section of theamplifler has a top header I5 andthat the risers I6 rise fromthese headers I5, of which five are shown,and connect with the header I1 which in turn connects with the drums I,2 and 3, within the boiler. These connections (as shown in Figs. 1, i

I'he boiler amplifier device 2 and 3) each include the pressure gauges23, 20a,

v and 29 of the pipes 30 and 3l. Bolts 32 clamp the iianged edges of thepipes tightly together and hold the orice vplatein place. This enablesViri case o! necessity the removal and replacement of the orifice platesby simply -loosening a few of the bolts, slipping out the oriiice plate,replacing it and then tightening the bolts once more after the neworiiice plate is installed.

It will be observed that the opening of the oriilce plate is preferablycountersunk r flared with the small diameter side of the opening towardsthe risers I6 and the large diameter side of the opening towards thedrums I, 2 and 3, thus allowing for rapid expansion and separation ofsteam and water in the boiler.

In Fig. 7 is shown a construction of the header and illustrating theconstruction of any of the headers I5 or 21. It will be observed thatthe end of the header is stopped or (plugged by the plate 36 which iswelded in by a mitered joint. Fig. 8 is a section of the header of Fig.7 taken on the lines 8 8, and shows the method of joining the tubes ofthe ampliiier system 3 to the header.

Fig. 9 illustrates a modication of Fig. 8 consisting in the provision ofcollars 31 which are welded to the header and the tubes 3 are welded tothe collar. This has the advantage over the connection illustratedin-Fig. 8, in which the tubes 6 are welded directly to the header, inthat it facilitates annealing and stress relieving of the welded joint.l

It is sometimes desirable to provide two headers at the bottom and twoat the top of the tube system of the amplifier, and such a constructionis shown in Fig. 10. In this construction the pipeil leads the waterfrom thepump I (not shown in the figure) through the connections 2S-26into the headers 21-21, the tube system 6 and top headers I -I5, thenthrough .pipes I6a and I6b to pipe- I'Ii, whence it is returned to theboiler drums in the manner previously described.

Figs. 11 and 12 illustrate a construction in which the riser pipes I6connect directly with the boiler drum I without an intervening header. y

Fig. 11 is a plan view of this construction and Fig. 12 a sideelevation.

Fig. 13 shows a sectional elevation of a coa `stoked amplifier of theinvention. Due to the necessity of providing space for the grates in thecombustion area of the amplier, the'lower ends of the tubes are spreadapart and two headers 21, 21, are provided at the inlet 4side of thetube system which is curved above the fires to the junction with thesingle top or outlet header l5.l

Fig. 14 is a side elevation of a coal stoked amplier showing the stoker38 and the tube system iler structure. Furthermore, as shown in Figs. 13

and 14, a bridge wall 44 may, if desired, be used where the amplier isstoked.

The operation of the boiler amplifier is as Iollows: The pipes 1, 8 and9 connect with the boiler drums I, 2 and 3 below the water level in thedrums. As seen in Figs. land 2, the boiler is represented as oi' aconventional type comprising one or more drums I, 2 and 3, having anatural circulation. The pipes 8 and 9 connect with pipe 1 which in turnconnects with the pump I0. The pump III draws the water down from theboiler drums and forces it through the pipe II to the header 21,"` thenup through the tubes of the ampliiier system 6, and through the headersI5, pipes I3, orifice plates I8, I8a, lsb, I8c and i3d (shown in Fig.3), and thence into header I1, from which it drops back into the drumsas separated steam and water. Due to the control exerted by thepressureprovided by the pump I0 and the restriction effected by the orificeplates I3, the water and steam flowing through the -system cannotseparate until they have passed into the boiler drum where there issuflicient space for expansion. A higher pressure is maintained in theamplifier system than-in the boiler drums; for example, if the pressurein the boiler drums is 150 lbs., the pressure in the aming and cleaningthe tube system of the amplifler, a blow-0E valve 34 is provided belowthe bottom header of each section of the tube sysy the water and steamarel forced by steam pres- 6, each section of the tube system beingprovided with top headers I5 and bottom headers 21 as in Fig. 13.

'Ihe walls of the amplifier combustion chamber may conveniently be builtin sections corresponding to the sections of the tube system of theamplier and these sections are indicated in Fig. 2 at 39, 40, 4I, 42 and43. It is thus possible, where it is desired, to obtain access to thetube system orto remove a single section thereof, to break out a singlesection of wall, disconnect the tube section and remove it through theside of the amplisure from the top portion of the amplifier tube systemand out through the blow-oil. valve in a direction opposite to normalcirculation. A back wash blow down eiect is thus produced.

In the forni of the invention where furnace coal is stoked in to providethe heat for the ampliiier, the tubes are arranged to accommodate thegrates 35, and to this end the tubes of the amplier diverge, from thecircular formation shown in Fig.,4. As will be seen in Fig. 13 the tubesseparate at the bottom and the header 21 is duplicated on either side asshown at 21, 21 in Fig. 13. The pump connections are, however, the sameand the pipe system oi! the ampliiier is constructed in sections asshown in Fig. 14.

The operation of the amplifier is theA same as in the circularconstruction lwhich. is employed when oil or powdered coal are used asfuel as shown in Fig. 4.

Having thus described my invention, what I claim is:

1. A boiler amplifier comprising a wall delining an open endedcombustion chamber, the open end communicating with the combustionchamber of a boiler, a steam generating tube system within saidamplifier combustion chamber consisting of a plurality o1' sections ofsubstantially rounded contour embracing fires substantially centrallypositioned therein, each section of said tube system being provided withan inlet header and an outlet header with inlet and outlet pipes at endsof said sections most remote from each other, and adapted and arrangedto admit and discharge iluid from said section, pipe connections-betweenthe drums of said boiler and said inlet headers and pipe connectionsbetween said A drums.

outlet headers and said drum. a pump between said drums and said inletheaders whereby water from said drums is forcibly circulated throughsaid. steam generating tube sections and pressure drop means betweensaid outlet headers and said drums whereby lsteam and water from saidtube systems are prevented from separating until the flow of steam andwater has entered said 2. A boiler amplifier consisting of a boilerextension comprising a pump. pipe connections from the drums of a boilerto said pump, pipe connections from said pump to a tube system of curvedconformation within which the furnace fires are centered. said tubesystem enclosing a combustion area communicating with the combustionchamber of said boiler. said tube system comprising tubular sections.headers at top and bottom of said ltube system, and risers connectedfrom said top headers to said boiler drums through which water and steamare discharged from said tube system into said drums and pressure dropcontrolling means positioned at the outlets of said risers into saiddrums whereby separation of said water and steam is prevented until theilow has passed said pressure drop means and entered said drum.

3. A boiler amplifier comprising a tube system consisting of a pluralityof sections each comprising a bottom inlet header and a top outletheader. and tubes associated with said headers v of curved contourembracing fires substantially LAboilerampliiieraccordingtoclaimSin whichvalve means are provided whereby each section may be closed on the inletside and other valve means below said section for blowing down saidsection. 4

5. A boiler amplifier according to claim 3 wherein .the tube sectionsare of arcuate form having an inlet header at the 'foot of each side ofthe arch; a single outlet header at the top joining the tubes formingeach side of the arch; and a coal burning grate within the ambit of saidarch.

6. A boiler ampliner comprising a tube system consisting of a pluralityof detachable sections each comprising a bottom inlet header and a topoutlet header and tubes associated with said headers of curved contouradapted to embrace fires substantially centered therein; a main pipeleading from the drums of a boiler and connecting with each of said tubesections through separate branch pipe connections leading to the inletheaders of each tube section: a pump located in said main pipe; separateriser pipe connections leading from said outlet header of each tubesection to a manifold header connecting with said drums and pressuredrop devices located in said separate riser pipe connections adJacent'said manifold header connecting with said drum; and valve means forcutting each section of said tube system out of operation.

v'1. A boiler ampliner according to claim 6 in which each section ofsaid tube system is come posed of two semicircular groups of tubes, eachgroup having a bottom inlet header and a top outlet header; suitablepipe connections to each inlet header from the main pipe leading fromthe boiler drums and suitable riser pipe connections from both said topoutlet headers to said manifold header. MICHAEL C. CROTI'Y.

